We found that cerebellar granule cells (CGC) undergo spontaneous cell death after culturing in vitro for about 17 days. This cell death is characterized by DNA fragmentation, chromatin condensation, and requirement for RNA and protein synthesis, indicating the occurrence of apoptosis. This age-induced apoptosis is accelerated by N-methyl-D-aspartate (NMDA) but delayed by aurintricarboxylic acid (ATA), tetrahydroaminoacridine (THA), anti-oxidants and NMDA receptor antagonists. Overproduction of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA and protein precedes the cell death. This over-production is hastened by NMDA but diminished or prevented by ATA, THA, actinomycin-D or cycloheximide. Antisense oligodeoxyribonucleotides to GAPDH effectively protect against apoptosis, while the corresponding sense oligonucleotides are ineffective. Thus, GAPDH is linked to neuronal apoptosis. Cerebral cortical neurons also undergo age-induced apoptosis in culture and this form of cell death also involves GAPDH over-expression. Low potassium-induced apoptosis of CGC is blocked by cycloheximide and partially protected by actinomycin D, THA, and antisense oligonucleotides to GAPDH. Moreover, BDNF and bFGF provide efficient protection, while NT-3 is inactive. The neuroprotective effect of THA could be related to its therapeutic action in the treatment of Alzheimer's disease.